An animal rights group is appealing Illinois' denial of its proposal to install highway signs in memory of cattle that died when trucks hauling them flipped in two separate wrecks.

People for the Ethical Treatment of Animals said Thursday that it has written the Illinois Department of Transportation with its appeal. The state previously denied the application, saying the state's Roadside Memorial Act specifies that only relatives who lost loved ones in highway crashes may request memorials.

PETA has asked Illinois officials to reconsider, saying the cows suffered and are "worthy of remembering."

IDOT spokesman Josh Kauffman said Thursday that the department has received PETA's letter and it is under review. PETA wants to buy the markers, which if approved would be installed in suburban Chicago and northwest of Peoria.